I hardly like to show you these pictures as they're such poor quality, but they're all I have of this bike and they may be of some interest in demonstrating the scope of smaller-size bikes.
I think it must be a 1997 C16R, as its serial number begins A607 - i.e, built in July 96 as Cherrybomb has explained it to me, so for autumn sale, so for 97 model range.
It's a size 15, which Orange say is designed for height range 5-3 to 5-7. I originally built it for my son when he was 9 and 4-10 and it was then in the form of the first picture with very short post and DH stem. It later went on to another 9 year old, who is now 11 hence I've just fitted the longer post and stem in the second pic (please ignore errant bar end!)
With Z2 Light fork and STX-RC/M600/XT chainset(!) and Merlin wheels, this is a 25lb bike and that's pretty light for a child's bike. They may hanker after cheap full-suss bikes like their pals, but once they're out in the countryside and they've arrived at the top of a hill miles before all the rest, both my son and the new owner were perfectly happy with a classy retro steel hard-tail. My son took a whole hour off his previous best time around Bewl Water the first time he went there with the Orange and that amounted to a much more pleasant day out for his parent as well as for him.